https://gsap.com/community/forums/topic/8867-cssruleplugin-not-picking-up-complex-rules/
CSSRulePlugin not picking up complex rules - GSAP - GSAP
There seems to be an issue with the CSSRulePlugin with complex rules. The getRule method returns null so you get the "Uncaught Cannot tween a null target."...
picking upcomplex rulesgsap